Mazda CX-3 2016–2026 — technical service bulletin

Bulletin SA-056-25 · NHTSA communication 11026354 · issued Nov 27, 2025

Technical service bulletin

communication type

Power Train

component

2016–2026

model years

vehicle entries

Official summary

When inspected, the differential or PTO oil is dark or black. This is considered normal and NO repair should be performed. During production, differential ring and pinion gears receive a manganese phosphate coating (commonly referred to as black oxide). This coating forms a porous, oil-retentive surface that improves boundary lubrication and reduces adhesive wear during initial contact cycles. Designed as a sacrificial layer, it is gradually removed under load throughout the break-in process. As a result, after the first few hundred miles, or at the initial gear oil service interval, the lubri

Vehicles covered

What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.